Instantly share code, notes, and snippets.

Embed
What would you like to do?
OpenSCAD source code: Tour Easy Front Derailleur Cable Clamp
// Tour Easy Derailleur Cable Clamp
// Ed Nisley KE4ZNU - June 2017
/* [Build Options] */
Layout = "Build"; // [Build, Show]
/* [Extrusion] */
ThreadThick = 0.25; // [0.20, 0.25]
ThreadWidth = 0.40; // [0.40]
function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
/* [Hidden] */
Protrusion = 0.01; // [0.01, 0.1]
HoleWindage = 0.2;
ID = 0;
OD = 1;
LENGTH = 2;
/* [Cable Clamp] */
FrameOD = 25.7; // Tour Easy has hard inch tubing + paint
Ferrule = [1.5,5.1,12.0]; // cable ferrule
EntryPoint = [0,13,60]; // cable entry to derailleur, +Y to rear of bike
CableTilt = -20; // tilt from parallel to frame tube
CableTheta = 0; // rotation around clamp from +X axis
/* [Screws and Inserts] */
ClampScrew = [3.0,5.5,35.0]; // M3 button / socket head cap screw
ClampWasher = [3.7,7.0,0.7]; // M3 washer
ClampNut = [3.0,6.0,4.0]; // M3 nylock nut
/*
ClampScrew = [4.0,7.0,25.0]; // M4 button head cap screw
ClampWasher = [4.5,9.0,0.8]; // M4 washer
ClampNut = [4.0,8.0,5.0]; // M4 nylock nut
*/
NutShift = -0; // slide bushing toward nut for clearance
//- Set clamp ring dimensions
WallThick = 10.0;
BushingSides = 8;
Bushing = [ClampScrew[ID],
// ClampWasher[OD]/cos(180/8) + 4*ThreadWidth,
Ferrule[LENGTH]/cos(180/BushingSides),
ClampScrew[LENGTH] - 2*ClampWasher[LENGTH] - ClampNut[LENGTH]];
Ring = [FrameOD + HoleWindage,FrameOD + 2*WallThick,Ferrule[LENGTH]];
ClampScrewOC = IntegerMultiple(FrameOD + ClampWasher[OD],1);
echo(str(" screw OC: ",ClampScrewOC));
ClampKerf = 0.75; // kerf between separated halves
NumSides = 8*4;
//- Adjust hole diameter to make the size come out right
module PolyCyl(Dia,Height,ForceSides=0) { // based on nophead's polyholes
Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2);
FixDia = Dia / cos(180/Sides);
cylinder(r=(FixDia + HoleWindage)/2,h=Height,$fn=Sides);
}
// Construct things
module ClampRing() {
difference() {
union() {
cylinder(d=Ring[OD],h=Ring[LENGTH],$fn=NumSides); // basic ring
for (j=[-1,1]) // screw bushings
translate([Bushing[LENGTH]/2 + NutShift,j*ClampScrewOC/2,Ring[LENGTH]/2])
rotate([0,-90,0]) rotate(180/BushingSides)
cylinder(d=Bushing[OD],h=Bushing[LENGTH],$fn=BushingSides);
intersection() {
rotate([CableTilt,0,CableTheta]) // reinforce cable ferrule
translate([(Ring[ID] + Ring[OD])/4,0,Ferrule[LENGTH]/2])
rotate(180/8)
cylinder(d=3*Ferrule[OD] + 0*ThreadWidth,2*Ferrule[LENGTH],center=true,$fn=8);
cylinder(d=2*Ring[OD],h=Ring[LENGTH],$fn=NumSides); // basic ring
}
}
translate([0,0,-Protrusion]) // frame tube
cylinder(d=Ring[ID],h=Ring[LENGTH] + 2*Protrusion,$fn=NumSides);
rotate([CableTilt,0,CableTheta]) // cable ferrule
translate([(Ring[ID] + Ring[OD])/4,0,-0.25*Ferrule[LENGTH]]) {
rotate(180/8)
PolyCyl(Ferrule[OD],Ferrule[LENGTH],8);
rotate(-22.5)
PolyCyl(Ferrule[ID],2*Ferrule[LENGTH],4);
}
for (j=[-1,1]) // screw holes
translate([Ring[OD]/2,j*ClampScrewOC/2,Ring[LENGTH]/2])
rotate([0,-90,0]) rotate(180/6)
PolyCyl(Bushing[ID],Ring[OD],6);
for (i=[-1,1], j=[-1,1]) // screw & nut seats
translate([i*(Bushing[LENGTH]/2) + NutShift,j*ClampScrewOC/2,Ring[LENGTH]/2])
rotate([0,i*90,0]) rotate(180/BushingSides)
cylinder(d=Bushing[OD],h=Bushing[LENGTH],$fn=BushingSides);
translate([0,0,Ring[LENGTH]/2]) // slice it apart
cube([ClampKerf,2*Ring[OD],2*Ring[LENGTH]],center=true);
}
}
//- Build things
if (Layout == "Show") {
translate(EntryPoint)
cube(1,center=true);
ClampRing();
}
if (Layout == "Build") {
ClampRing();
}
@ednisley

This comment has been minimized.

Show comment
Hide comment
@ednisley
Owner

ednisley commented Jun 5, 2018

More details on my blog at https://wp.me/poZKh-7za

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment